After Manchester City moved to the summit with a hard-fought triumph of their own against Tottenham just over 24 hours earlier, the Reds were made to sweat in the April sunshine by a side occupying the final relegation spot in the table.
Eventually, Liverpool found a clever way to break down a stubborn Cardiff defence, Georginio Wijnaldum meeting Trent Alexander-Arnold's corner with a powerful first-time finish.
A foul on Mohamed Salah by Sean Morrison allowed James Milner to wrap up a ninth successive win in all competitions for Jurgen Klopp's side from the penalty spot, meaning they now sit two points clear of the reigning champions, who have a game in hand.
After booking their place in the Champions League semi-finals in midweek, Liverpool returned to domestic duties knowing only a victory would suffice in the Welsh capital.
Roberto Firmino carelessly lifted their best chance of the first half over the top, wasting good work by fellow forwards Salah and Sadio Mane as his left-footed shot cleared both the advancing Neil Etheridge and the crossbar.
Cardiff's goalkeeper was needed to make a close-range save to deny Salah shortly after, though Liverpool did not pick up the pace until after the interval, leading to Wijnaldum’s 57th-minute strike from a well-worked set piece.
Having wasted a free header with the score at 1-0, letting Alisson off the hook after the goalkeeper had failed to deal with a corner, Morrison was adjudged to have pulled down Salah in the other penalty area, allowing Milner - who replaced fellow substitute Fabinho due to a head injury - to put the result beyond doubt.
Over to you, City
For some time now, the Manchester derby has appeared the crucial fixture in deciding who will be crowned champions.
Pep Guardiola’s side can leapfrog Liverpool again with victory at Old Trafford on Wednesday, putting them in pole position to retain their title with three games remaining. Astonishingly, Klopp’s squad could end up as bridesmaids on 97 points.
